Armature of electro motors and generators



Aug. 13, 1 92 9.

F. W. LANCHESTER Fiied Dec. 17, 1926 INVENTO-K F. w. LANCHESI 'ER ARMATURE OF ELECTRO MOTORS AND GENERATORS Filed Dec. 17. 1926 2 Sheets-Sheet 2 HWeNTarQ Q M L anal 16.9%,

Patented Aug. 13, 1929.

UNITED STATES FREDERICK WILLIAM LANCHESTER, OF MOSELEY BIRMINGHAM, ENGLAND.

ARMATURE OF ELECTED MOTORS AND GENERATORS.

Application filed December 17. 1926, Serial No.

The present invention relates to dynamo electric machines and refers more particularl to improved constructions of armature for direct current motors and generators intended to be coupled to prime movers such as internal combustion engines.

The present invention has for its object to provide improved constructions of armature winding and mountings. It is usual in armatures constructed in the customary manner to limit the peripheral speed for meehanicalreasons to some 3000 or 41,000 feet per minute. According to the present invention it is possible to run armatures with safety up to 18,000 or 20,000 feet per minute with a corresponding increase in output and reduction in weight.

Furthermore, it is possible to dismantle and re-erect the dynamo electric machine en bloc without disturbing the commutator or armature connections.

Referring to the accompanying diagrammatic drawings Figure 1 illustrates an end view of a convenient construction in accordance with the present invention.

Figure 2 is a longitudinal sectional view thereof, and

Figure 3 is a vertical longitudinal sectional view of a modified detail.

In one mode of carrying the present invention into effect as is illustrated by way of example in Figures 1 and 2, an armature core a of the ring type is built up of a number of annular discs or laminations which are perforated at I) either by punching individually or drilling en masse with a number of holes or slots near the periphery, the said discs being held together by a number of rivets (not shown) passing through same and including on each flank an annular disc 0, c of insulating material such as vulcanized fibre or compressed paper. The winding consists of a well insulated wire (Z threaded through the holes aforesaid and wound as a single layer on the interior of the ring a. In order to avoid the necessity of passing an undue length of wire through the holes when winding each commutation section of the winding is Wound as a single length and its ends are serrated by pressure in suitably formed dies so as to engage with one another and then wound with a few turns of binding Wire to form a junction capable of resist- 15C,501, and in Great Britain January 4, 1926.

ing tension, the ends of the said binding wire being utilized to connect to the risers e from the commutator se ments f; the junctions of the wires so formed being grouted with soft solder and served with insulation tape. The junctions in question are preferably formed at some point on the interior of the ring and the risers from the commutator are arranged radially so that under the influence of centrifugal force they are in pure tension and not subject to bending stresses. The armature so wound is placed between the platen of a hydraulic press and the windings where exposed on the flanks of the ring are perceptibly flattened to form a bea ing for the supporting flanges.

rilternati l flattened-section (e. g. rectangular or square) wire may be employed, thus removing the necessity for such pressing operation.

Supporting flanges g, 71. are provided on either side of the armature and these flanges carry spigots forming an approximate fit on the interior of the winding in order to centre the armature and bolts are provided between the positions assigned to the risers c by which the supporting flanges may be drawn together and firmly grip and support the armature between them. The flange 9 is furnished with a disc or arms conne 'ng to a central boss m by which it is keyed to the shaft or spindle n and drawn up by the nut 1, thus forming the driving connection between the armature proper and spindle. The commutator is constructed of copper bars f and mica insulation in the usual manner held between terminal plates Z 0, one of which embodies a supporting sleeve 1 provided with an externally threaded portion upon which a nut 22 is fitted.

The flange h on the commutator side of the armature is bored to a diameter somewhat larger than the commutator and the space between the said bore and the commutator is occupied by a bush 8 of insulating material. A convenient construction in this respect is to cut two annular grooves 25, f; in the flange and provide segmental rings 2a a which are drawn together by screws o, thus contracting the portions w, w of the flange (these portions being saw cut at intervals to provide sufficient yield.)

Alternatively as indicated in Figure 3 I arrange between the bore aforesaid and the conical bore and provide a segmental conical sleeve 3/ seating upon the lnsulation s, which in turn seats upon the commutator face. The

liner aforesaid is bolted to the flange 71: and when tightened up grips the insulation and so forms a centering and supporting medium betweenthe flange and the commutator, by this means holding the commutator bars rigidly against centrifugal force. The portion of the commutator to which the brushes are applied is that projecting externally from the armature assemblage.

The inner surface of the sleeve 9 is somewhat larger than the exterior surface of the boss (which is externally treaded as shown) so as to enable the securing nut r to be removed by the insertion of a tubuar spanner. This also enables a flange drawer to be attached to the boss 1', thus enabling the two flanges, armature core and windings and commutator to be removed en bloc with ease.

The slots through which the armature windings are taken in the periphery of the core may be arranged radially.

If desired, in cases where it is not necessary to remove the armature en bloc from its shaft, the commutator may be attached to the shaft in customary manner; in this case I prefer to retain the external support for the commutator which is provided in the ex ample described with reference to Figures 1 to 3', since this provides an auxiliary restraint against centrifugal force, while at the same time more securely centering the armature itself.

Having now described my invention what I claim as new and desire to secure by Letters Patent is 1. An armature of the Gramme or ring type for a dynamo electric machine including a set of laminations, perforations near the outer peripheries of said laminations, conductors passing through said perforations and over the end and inner surfaces of said set, and a pair of end plates bolted to each other and abutting the portions of said conductors which pass over said end surfaces so as simultaneously to grip said conductor portions and said laminations by friction alone.

2. An armature as claimed in claim 1, wherein one of said end plates encircles and acts as a steady on the exterior of the commutator bars, thereby exercising an auxil iary restraint thereupon against centrifugal force and at the same time securely centering the armature itself.

An armature as claimed in claim 1 formed as a rigid unit including a commutator, the unit being mountable upon and demountable from a prime mover shaft with maintenance of rigid mechanical connection between the armature and commutator.

In testimony whereof I have signed my name to this specification.

FREDERICK WILLIAM LANCHESTER'. 

